The analysis of a pool of data which is determined by measuring, including the statistical analysis of the reciprocal relationship between the data and the data correlations thereof and the analysis with respect to the future development of these data, that is to say what is known as trend prediction, is a wide-ranging field of application. For trend prediction, trend models are usually created which are based on the traditional approach of time series analysis. Trend analysis and trend prediction are statistical tools which make it possible to better interpret measured data or also data determined in another way. Trend analysis can be used for trend prediction in order to be able to make and verify statements relating to the trend of the measured data.
Although a time-dependent series of data points determined by measuring can in principle be used in any trend prediction method, the present invention and the problem addressed thereby are described in the following with respect to a method and a device for trend prediction which is for use in an aircraft or spacecraft. In particular, the present invention is described in the following with respect to trend prediction with reference to measured oscillations at a component or system of an aircraft.
A method for predicting the failure of gas turbines in an aircraft is described for example in US 2011/0040470 A1.
In aircraft, in particular in passenger aircraft, for safety reasons alone fixed predetermined maintenance intervals are always to be observed, within which the components and systems of an aircraft have to be checked, serviced and repaired. These intervals are determined in such a way that it is ensured that the respective components and systems are sufficiently safe and functional until the next maintenance interval. Therefore, the corresponding maintenance intervals are typically selected together with a slack time so as to be correspondingly well-spaced.
However it is problematic that, using this approach, systems of an aircraft are also sometimes serviced despite the fact that they are, for example, still fully functional and that the maintenance thereof is in fact unnecessary. It is thus clear that in this way, due to unnecessary maintenance which is nevertheless carried out without knowledge of the actual circumstances, additional costs are incurred.
In addition, for passenger aircraft for example, the time periods available for maintenance work are only very short. Conventionally, this work is carried out during immobilisation times of the aircraft between the arrival of an aircraft at the terminal and it leaving the terminal again, for which usually only a short time period of approximately 90 minutes is available. This means that it is thus desirable to collect previously corresponding findings relating to the condition of a system or component in the aircraft.
The air-conditioning system, which is usually also referred to as HVAC (heat, ventilating and air conditioning), is particularly significant in an aircraft both with respect to functionality and for the comfort of the passengers. The air-conditioning system is intended both to supply the passengers in an aircraft with fresh, temperate air and to cool electronic systems. For this purpose, the air-conditioning system uses recirculation fans and filters to make it possible to circulate and thus clean the cabin air. The filters used can, however, become blocked over time, associated supply lines can become dirty and the fans can for example become faulty, for example due to failures of the electric motors or due to fractures of the fan blades. Here, it is problematic that blockage of the filters in particular is very difficult to predict since it always depends on the surroundings of the respective filters and the field of application. This thus results in these filters being checked very frequently on site, and this involves additional checking time during the immobilisation times of the aircraft.
This is a situation which understandably is to be avoided.